The present invention relates to methods and systems for providing a wide area centrex toll service, but more particularly, to a wide area centrex toll service which makes use of a switch-based multi-switch business group architecture.
In a basic wide area centrex service, a group of telephone lines are provided with business features which are similar to those provided by a PBX or a PABX. These features are provided through a central office exchange of the public telephone network but without the customer having to purchase and maintain a private exchange.
For example, wide area centrex provides intercom capabilities to the lines of a specified business group so that a business customer can dial other stations within the same group using extension numbers, such as a two, three or four-digit number, instead of the full telephone number associated with each called line or station. Improvements in centrex services and area wide centrex are disclosed in U.S. Pat. Nos. 5,247,571 and 5,422,941.
In order to provide wide area centrex services to customers who have locations which are normally connected via toll lines, a multi-switch business group (MBG) service can be offered to meet the needs of those customers. These customers will often be served by multiple switches in the same local access and transport area (LATA). Organizations such as banks, real estate firms, health care systems, school systems and governmental agencies will often demand centrex services deployed across each of their locations even though they may be served by a toll line.
MBG allows centrex and private network traffic to be placed on public CCS7 facilities while retaining customer group identity. When an MBG call is routed over a public CCS7 trunk, the identity of the customer group is sent to the destination switch. This allows a switch to identify calls among members of the same customer group and handle them differently than other calls. MBG extends many centrex services across the CCS7 network, supporting features such as network name and number display, reason display, etc.
Businesses that have multiple locations within a LATA but who cannot cost-justify private lines can use MBG to cost-effectively network those locations. Businesses now using a private line network can use MBG as an additional option for routing traffic and expanding their network to locations not served by private lines.
Generally, the customer is interested in forming a seamless communication network in terms of feature operation, and dialing patterns. It also would like its network to be transparent to calling clients and customers, with calls easily covered, routed and transferred throughout their network as though they were at a single location.
However, for multi-LATA businesses, many centralized hubs are linked into a multiple-hub arrangement. Multiple-hub operations have one or more relatively large locations, for example, main offices in more than one city. This means multiple points of concentration for the network access and support services. Often, multiple-hub customers are inter-LATA, and require the services of one or more inter-exchange carriers (IECs). Although the wide area centrex and MBG services might be offered by one carrier, customers with multiple hubs may wish to use a different carrier for long distance or toll traffic. Unfortunately, MBG service providers are unable to provide this service to customers having locations served by an IEC, since MBG service was never meant to be offered to inter-LATA locations.
The customer's ability to select an inter-LATA or toll carrier is made possible by a Regulation called equal access (EA). Equal access is an operating company tariff which provides a given subscriber access that is equal in type and quality to every inter-LATA carrier. Each IED has a dialing arrangement, call-screening technique, routing procedure, billing record, and signalling protocol are required to implement the EA environment.
The EA concept originated in the United States with the modified final judgment (MFJ) of 1982 in which AT&T lost its long-distance monopoly and was also required to divest itself of the Bell operating companies (BOCs). This divestiture action resulted in the formation of seven regional holding companies, each comprised of a number of the original BOCs. Manufacturers have implemented the EA concept according to the regulatory requirements of the 1982 MFJ. The United States EA concept is built on the geo-politically defined local access and transport areas (LATAs). A LATA is a fixed non-overlapping geographic area determined at the time of the MFJ ruling. Telecommunication services within a LATA, including local and toll calls within a LATA, are carried by Bell operating companies. Inter-LATA traffic must be carried by an inter-LATA carrier (IC). Today, intra-LATA competition is now allowed in the United States. That is, subscribers have the capability of selecting an alternate intra-LATA carrier for intra-LATA calls as well as an inter-LATA carrier for inter-LATA calls. The BOC must transfer inter-LATA traffic to the IC directly from the end office (EO) or via an intermediate switch called an access tandem (AT). The physical location of an IC within a LATA is referred to as the point of presence (POP).
In order to enable MBG basic call service, certain access in routing restrictions are assigned by the customer to individual lines using line privileges. For example, an MBG identifier is used to uniquely identify an MBG in the network. A customer's line belongs to one and only one MBG. A sub-group identifier uniquely identifies a group of lines within an MBG. If an MBG has sub-groups, an MBG line belongs to one and only one sub-group within an MBG. Line privileges (LP) specify the line privileges associated with an MBG line. Certain feature operation decisions are based upon line privileges.
In order to enable multi-switch business group services, certain information about the calling customer must be sent on the CCS7 signalling link between two switches serving the business group customer. This information is usually carried via the multi-business group MBG and generic address parameters in the ISUP message sent between SS7 capable switches.
However, it is not presently possible to populate the ISUP message with the necessary parameters which are required to support services which require multi-business group and generic address parameters to be transported for both intra-LATA and inter-LATA calls. That is on toll lines which may belong or be used by different inter-exchange carriers.
Accordingly, a need exists for a wide area centrex toll service which makes use of a multi-switch business group switch-based architecture which is capable of providing MBG services over locations served by various inter-exchange carrier facilities.